The 8-year-old is too young to bluff, too young to read a bluff, and too young to buy into the abstract and conceptual rewards of playing a game like I Doubt It to win. Consequently, on everybody's every turn, he would say "I doubt it!"

This is a procedurally legal way to play, but such a debased strategy that the game can't survive it.

People who bring James Bond or Hydra into Spione are doing the stylistic equivalent.